The present invention relates to an airbag system including a horn switch, and more specifically, to an airbag system in which only a module cover moves to turn on the horn switch when the module cover is pushed.
A driver-seat airbag system mounted on a steering wheel of a car includes a retainer (base plate); an airbag disposed in the retainer in a folded state and having a gas inlet with periphery mounted to the retainer; a module cover covering the folded airbag; and a gas-generating inflator (gas generator) provided at an outer periphery side of the retainer in a radial direction. When the inflator is activated to generate gas, the airbag expands to tear open the module cover, so that the airbag deploys in a vehicle cabin to protect an occupant in a driver seat. A steering wheel generally has a function of blowing a horn (warning horn) in addition to a function of steering a car.
A driver-seat airbag system has been proposed in which a horn switch is turned on to blow the horn when a module cover is pushed (refer to Japanese Patent Publication (Kokai) No. 2001-114057). The airbag system is constructed such that the retainer is fixed to the steering wheel and only the module cover moves. Specifically, the retainer has a sidewall extending vertically from an outer periphery thereof, and a vertical wall of the module cover is supported on the outer periphery of the retainer sidewall to be movable vertically. A fixed-side contact is disposed on a fixed-side contact support section projecting from the outer periphery of the retainer sidewall, and a moving-side contact facing the fixed-side contact is disposed on a bracket provided on the outer periphery of the vertical wall of the module cover.
When an operator pushes the module cover, the module cover moves downwardly toward the retainer, so that the moving-side contact contacts the fixed-side contact to turn on the horn switch, thereby blowing the horn. When the module cover is released, the module cover is urged upwardly by a coil spring provided between the fixed-side contact and the moving-side contact (between the fixed-side contact support section and the bracket) to return to an initial position.
In the conventional airbag system, the fixed-side contact, the moving-side contact, and the coil spring for urging the module cover in the opposite directions are disposed at the outer periphery side of the airbag and the retainer. Accordingly, the entire airbag system inevitably becomes large in the radial direction, thereby making it difficult to reduce the size thereof.
In view of the problem described above, an object of the present invention is to provide an airbag system in which only a module cover moves to turn on a horn switch when pushed, thereby reducing a size of the airbag system.
Further objects and advantages of the invention will be apparent from the following description of the invention.